The present invention relates generally to turf aerating apparatus, and more particularly to novel tines for use with turf or soil aerating apparatus and which reduce the force required to effect turf penetration through substantial reduction in the frictional drag acting on the tines.
It is a common practice in the treatment of certain soil based turf to aerate the turf so as to stimulate root growth and generally effect a dense heartier turf. Such aeration is conventionally accomplished through passing either slicing tines or coring tines over the turf surface. The use of slicing tines results in relatively deep blade type slice cuts being made in the soil, while the use of coring tines results in the removal of generally cylindrical shaped plugs or cores of turf and soil from the ground leaving relatively small holes. Both techniques lead to aeration of the turf and admission of moisture to stimulate root growth.
In the use of coring tines to remove turf plugs or cores up to approximately 11/2 inches in length, it is conventional to mount a plurality of coring tines generally radially on a cylindrical shaped wheel or drum which may be caused to roll over the turf surface while supported for rotation about a generally horizontal axis such that the tines penetrate the turf. The tine support drum may be drawn by a tractor or other vehicle so as to facilitate movement across the turf surface to effect the desired aeration. See, for example, U.S. Pat. No. 3,022,833 to Reaser; U.S. Pat. No. 3,643,746 to Dedoes; and U.S. Pat. No. Re30,705 to Hines. U.S. Pat. No. 3,264,877 to Boxrud discloses a somewhat similar apparatus employing generally radial tines or probes to effect soil sampling. Where coring tine penetration of greater than approximately 11/2 inches is desired, aerating machines are generally employed in which a plurality of tines are caused to undergo substantially vertical reciprocating movement during turf penetration. See, for example, U.S. Pat. No. 3,834,464. Turf plugs may also be selectively removed from a soil surface by manual devices operative to remove single plugs or cores through manual manipulation. See, for example, U.S. Pat. No. 2,194,597 to Johnson, U.S. Pat. No. 2,899,231 to Steiner, and U.S. Pat. No. 3,098,672 to Husband. Still further, turf and soil aeration may also be accomplished by solid tines which are caused to penetrate the turf so as to effect shatter core aerification.
While the aforementioned turf aerating apparatus and techniques may provide generally satisfactory results, the prior turf aerating apparatus of both the rotary drum and vertical reciprocating tine type are limited in the number of tines which may be employed due to the force required to effect penetration of the associated tines into the turf. This limitation on the number of tines which may be employed on a given machine follows from the fact that the force required to effect penetration of a tine is determined in part by the frictional drag acting on the body of the tine. It thus follows that a tine which minimizes the frictional drag acting on the body of the tine will result in a reduction in the penetration force required to effect the desired depth penetration, thereby allowing a greater number of tines to be employed on a given machine and enabling a closer pattern of aeration holes to be provided in the turf or soil surface.